// JavaScript Document
my_txt.onChanged = function(){
 this.text = this._parent.my_array[2];
 };
Array.prototype.setChangeHandler = function(callback) {
 var len = this.length;
 for (var i = 0; i < len; ++i) {
  this.watch(i, callback);
 }
};

//usage example
my_array = ["a", "b", "c"];
createTextField("t0_txt", 0, 0, 0, 20, 20);
createTextField("t1_txt", 1, 30, 0, 20, 20);
createTextField("t2_txt", 2, 60, 0, 20, 20);

my_array.setChangeHandler(function (propName, oldVal, newVal) {
 _root["t" + propName + "_txt"].text = newVal;
 return newVal;
});
my_array[0] = "d";
my_array[1] = "e";
my_array[2] = "f";
/*=====

"setChangeHandler" should be called everytime the array length is 
changed.
And of course this is one-way communication from the array to the 
textfields.
To achieve mutual communication, TextField.onChanged, as has been 
suggested previously in this thread, should be added.

Cheers,
*/